Recently, the need to downsize various electronic devices makes it necessary to downsize the electronic components incorporated in the devices and improve the performance thereof. Also in multi-layered ceramic electronic components, such as multi-layered ceramic capacitors, it is strongly required to increase the number of layers and make the laminated unit thinner.
When a multi-layered ceramic electronic component as typified by a multi-layered ceramic capacitor is to be manufactured, ceramic powders, a binder such as an acrylic system resin, a butyral resin or the like, a plasticizing agent such as a phthalate ester, glycol, adipate ester, phosphate ester or the like, and an organic solvent such as toluene, methyl ethyl ketone, acetone or the like are mixed and dispersed, thereby preparing a dielectric paste for a ceramic green sheet.
The dielectric paste is then applied onto a support sheet made of polyethylene terephthalate (PET), polypropylene (PP) or the like using an extrusion coater, a gravure coater or the like to form a coating layer and the coating layer is heated to dryness, thereby fabricating a ceramic green sheet.
Further, a conductive powder of nickel or the like and a binder are dissolved into a solvent such as terpineol, thereby preparing a conductive paste and the thus prepared conductive paste is printed on the ceramic green sheet in a predetermined pattern using a screen printing machine and dried, thereby forming an electrode layer.
When the electrode layer has been formed, the ceramic green sheet on which the electrode layer is formed is peeled off from the support sheet to form a multi-layered unit including the ceramic green sheet and the electrode layer. Then, a ceramic green chip is formed by laminating a desired number of the multi-layered units to form the laminated body, pressing the laminated body and dicing the laminated body.
Finally, the binder is removed from the green chip, the green chip is baked and an external electrode is formed, thereby completing a multi-layered ceramic electronic component such as a multi-layered ceramic capacitor.
At present, the need to downsize electronic components and improve the performance thereof makes it necessary to set the thickness of the ceramic green sheet determining the spacing between layers of a multi-layered ceramic capacitor to be equal to or smaller than 3 μm or 2 μm and to laminate three hundred or more multi-layered units each including a ceramic green sheet and an electrode layer.
However, in a conventional multi-layered ceramic capacitor, since an electrode layer is formed on the ceramic green sheet in a predetermined pattern, a step is formed between the surface of the electrode layer and the surface of the ceramic green sheet where no electrode layer is formed. Therefore, in the case of laminating a number of multi-layered units each including a ceramic green sheet and an electrode layer, it is difficult to bond the ceramic green sheets included in the number of multi-layered units in a desired manner so that the laminated body fabricated by laminating the number of multi-layered units is often deformed and delamination of layers sometimes occurs.
In order to solve these problems, it has been proposed to eliminate steps on the surface of the ceramic green sheet by printing a dielectric paste on the surface of the ceramic green sheet in a complementary pattern to that of the electrode layer, thereby forming a spacer layer between neighboring electrode layers.
In the case where the spacer layer is printed on the ceramic green sheet between neighboring electrode layers in this manner, thereby fabricating the multi-layered unit, steps on the surface of the ceramic green sheet of each multi-layered unit can be eliminated and even in the case of laminating a number of multi-layered units each including a ceramic green sheet and an electrode layers and fabricating a multi-layered ceramic capacitor, it is possible to bond the ceramic green sheets included in the number of multi-layered units in a desired manner and it is possible to prevent the laminated body fabricated by laminating a number of multi-layered units each including the ceramic green sheet and the electrode layer from being deformed.